Method of manufacturing an electric device



Feb. s, 1938 IL.'R.PEITERS METHOD OF MANUFACTURING AN ELECTRIC DEVICEFiled Jan. 3, 1954 IN VENTUR LEQBFETERE Patcnted Feb. 8, 1938 METHOD orMANUFACTURING AN TRIO DEVICE ELEC Leo Peters, Garfield Heights,- Ohio,assignor to General Electric Company, a corporation of I New YorkApplicationJanuary 3, 1934, Serial No. 705,067

2 Claims.

My invention relates to electric incandescent lamps and similar devicescomprising an electric energy translation element, such as a filament,

mounted on leading-in wires and sealed in a bulb. More particularly myinvention relates to an improved joint or connection between the energytranslation element and the leading-in wires in suchdevices and to themethod of manufacture thereof. 7

Considerable trouble has been experienced with so called miniatureincandescent lamps such as those used in flashlights due to irregularityof performance. Heretofore the filament was generally clamped in a hookformed at the endof the leading-in wires or weldedthereto. These methodsare satisfactory where comparatively long filaments are used, althoughpoor connections are sometimes obtained and theactual point of contactbetween the filament and lead wire cannot be accurately controlled.Taking as a the flattened hook portion. Such differences in 1 filamentlength result in irregular performance of the lamps. 1

One of the objects of my invention is to provide a construction in whichthe filament length is accurately controlled. Another object is theprovision of a reliable joint between the filam'ent and leading-inwires.

Further features and advantages of my invention will appear from thefollowing description of species thereof and from the drawing.

In the drawing, Fig. l is an elevation of a lampcomprising my invention;Fig. 2 is a detailed view in perspective and at an enlarged scale showing a connection between the filament and lead wire; Figs. 3, 4 and 5are elevations, in section, of apparatus for forming the filament andlead wire connection in successive operating steps; and Fi'g. 6 is asection along line 6-6 of Fig. 3 showing filament supporting grooves. I

Referring to Fig. -1, an incandescent lamp is shown comprising afilament I II mounted on leading-in wires l2, l3. The said filament H)in Such a construction may this case consists of a straight wire, theends of which are embedded in the said leading-in wires. As shown inFig. 2, the ends of the leading-in wires have a definite predeterminedform, preferably rectangular in cross-section, and the filament i0 isembedded in at least one face of the square section, such as the faceIt. of leading-in wire 12.

ment from the point'll' to the end thereof. Thus the operative portionof the filament extends a definite distance between the inner faces l5,l6 of the leading-in wires l2, l3.

ince the filament consists of a hard metal such as tungsten and theleading-in wires The method of forming the joint between the filamentand leading-in wires is shown progressively in Figs. 3, 4 and 5.Referring to Fig. 3, the filament wire l0 lies on the face of a springactuated block or jaw l5 and in V-shaped grooves l6 (Fig. 6) in a lowerdie H in which the block I5 is mounted. A spring actuated block or jawI8 is mounted in the plunger or upper die IS, the width of said block l8being equal to the desired length of the operative portion ofthe'filament, and the width of the upper die l9 being equal to thelength of the operative portion of the filament plus twice theleading-in wire diameter. The upper die I9 is lowered so that the blockl8 engages and firmly and immovably holds the filament wire l0, afterwhich the upper die enters the lower die I1 and engages the circularleadingin wires l2, [3 which lie in the spaces between the sides of theblock 18 and lower die l1. As the downward movement continues, the upperdie l9 severs the filament wire I0 and the block I5 is forced downagainst the action of spring 20 until feet 2| thereon engage the die l1.As the upper die I9 continues to move down against the action of spring22, located between the block l8 and said upper die, and spring '20, theleadingin wires l2, 13 are pressed or molded into the rectangular orsquare space between lower die l1, block I 5, upper die l9 and block [8.The extreme ends of the filament are turned upward as shown in Fig. 5,and the leading-in wires are securely molded around the ends of saidfilament. It is filament between the lead wires is. very accuratelycontrolled since the said lead wires are so confined in the dies duringthe swaging and embedding step that they are not permitted, due to theirtendency-to flatten, to encroach upon "the of said Jaws and thenpressing and molding: a por- J'aw and around the translation element endextending therefrom to embed said ends ofthe translation element in theleading-in wires.

2. The method of mounting a filament on a. pair of leading-in wires byembedding the ends or said filament therein which consists in soconfining the said leading-in wires in dies duringthe swaging andembedding step that they are not permitted, due to their tendency toflatten, to encroach upon the intended eii'ectlve length of thefilament.

LEO R. PETERS- tion of a ieading-in'wire against each side of said

